Method for the production of therapeutically valuable 4-oxo-(beta-aminoethyl)-3, 4-dihydro-(benzo-1, 3 oxazine) and salts thereof



United States Patent M 3 244,704 METHOD FOR THE PriooUcTIoN or THERAPEU- TICALLY VALUABLE 4-OXO-(B-AMINOETHYD- 3,4-DIHYDRO-(BENZO-L3 OXAZINE) AND SALTS THEREOF Vittorio Molina di Gaudenzio, Novara, Italy (Strada Privata del Ciocche, Zona Baraggino Grande, Novara- Vignaie, Italy) No Drawing. Filed Juiy 12, 1963, Ser. No. 294,734 Claims priority, application Switzerland, Feb. 5, 1963, 1,392/63 1 Claim. (Cl. 260-244) wherein R is either the radical NH of a primary amine, or radical NH(alkyl) of a secondary amine monoalkyled with a lower alkyl, or radical N(alkyl) of a tertiary amine dialkyles with two lower alkyls, wherein n is 1,2 or more and R is either a hydrogen atom or a halogen atom, or the univalent radical --NH of a primary amine.

Moreover the invention relates to compounds produced according to this method.

It is the primary object of the invention to provide new valuable drugs, which in addition to analgetic, antipyretic and antip'hlogistic properties have a strong activity against various sorts of viruses.

With this and other objects in view, which will become apparent later from this specification, I provide a method for the production of 4-oxo-2-(13-aminoalkyl)-3,4- dihydrobenzo-1,3-oxazines, and of the salts thereof having the formula:

U 3H-(CHz)n-R .HCl

wherein R is either the radical -NH of a primary amine, or radical --NH(alkyl) of a secondary amine monoalkyled with a monoalkyl, or radical -N(alkyl) of a tertiary amine dialkyles with two lower alkyls, n denoting 1,2 or more and R denoting a hydrogen atom or a halogen or univalent radical NH of a primary amine, comprising the steps of mixing superior aldehydes and particularly acroleins when 11:2 in ethanolic solution with molar quantities of gaseous ammonia or of a corresponding primary or secondary amine, adding molar quantities of salicyl amide, substituted if desired, and treating the whole reaction mixture with hydrogen chloride.

The condensation is effected in 10% ethanol.

For the salicylamide components either unsubstituted salicyl amide comes into question, when R denotes a hydrogen atom, or substituted in the 5-position by halogen or an amino group, when the oxamines substituted in the 6-position are to be produced. For example the following substituted salicyl amides are in question:

m-Chloroor m-bromo-salicyl amide (=6 chloroor bromo 2-hydroxy-benzoic acid) or 3,244,704 Patented Apr. 5, 1966 m-Amino-salicylamide 5 amino-2 hydroxy-benzoic acid).

For the introduction of the radical R the following are used:

(a) For the radical NH of a primary amine: gaseous ammonia in ethanol,

(b) For the radical NH(a1kyl) of a secondary amine; a primary amine in ethanol, for example: N-monomethylamine or N-monoethylamine,

(c) For the radical N(alkyl) of a tertiary amine; a secondary amine inethanol, for example: N-dimethylor N-diethylamine.

The following examples are intended to explain the invention in more detail:

Example 1 In a solution of 56 grams (1 mol) acroleine in 10% ethanol 17 grams (1 mol) of gaseous ammonia are introduced. To this solution 137.1 grams (1 mol) of salicyl amide are added and the solution is cooled to 40 C. by flowing water.

At this temperature hydrogen chloride is introduced during 30 minutes. Stirring is continued a further halfhour without cooling whereafter the excess alcohol is distilled oil? in vacuum.

The remainder is now 4-0x0-2-(B-arninoethyl)-3,4-dihydro-benzo-1,3 oxazine in the form of its hydrochloride. The yield amounts to in theory.

The melting point of the product after recrystallisation from a mixture of ethanol and acetone 1:3 amounts to 310312 C. with decomposition.

Example 2 In a solution of 56 grams (1 mol) acroleine in 10% ethanol instead of ammonia as in the Example 1, 73.1 grams of diethylamine is added, otherwise one proceeds exactly as according to Example 1.

There results a 4-oxo-2-(fi-N-diethylaminoethyl)-3,4-dihydro-benzo-1|,3 oxazine in the form of its hydrochloride with a yield of 80%.

This product is likewise recrystallised from a mixture 1:3 of ethanol and acetone:

While I have herein described what may be considered typical and particularly useful embodiments of my said invention, I wish it to be understood that, I do not limit my invention to the particular details and dimensions described and illustrated, for obvious modifications will occur to a person skilled in the art.

What I claim as my invention and desire to secure by Letters Patent is:

A method for the production of 4-oxo-2-(fi-aminoalkyl)-3,4-dihydro-(benzo-l,3-oxazines) and the salts thereof having the formula H (CH2)2'Rl'HCl 0 wherein R is selected from the group consisting of primary, secondary and tertiary amino and R is selected from the group consisting of hydrogen, halogen and a primary amine, comprising the steps of mixing acrolein in a 10% ethanol solution with molar quantities of a member from the group consisting of gaseous ammonia,

a primary amine and a secondary amine, adding molar quantities of salicylamide, and treating the whole reaction 3 4 mixture with hydrogen chloride, said salicylamide being OTHER REFERENCES unsubstituted or substituted in the 5-position by a halogen Houbemweylz Methaden def Organischen Chemie, a P y amine- Ban XI/l Stickstoifverbindungen II, pp. 284-5 (Georg Thieme Verlag) (1957). References Cited by the Examine! 5 Ingold: Structure and Mechanism in Organic Chem- UNITED STATES PATENTS V y pp- 6945 (Cornell) 2,943,037 6/1960 Ohnacker et a1 260-244 WALTER A MODANCE Primary Examiner 3,116,292 12/1963 Polo-Friz 260244 NICHOLAS S. RIZZO, I OHN D. RANDOLPH, FOREIGN PATENTS Examiners. 570,639 2/1959 Belgium. ROBERT T. BOND, Assistant Examiner. 

